if it is being used as a means of exchange and people are willing to accept it for payment and using it consistently, the exchange rate to USD matters less than how much a loaf of bread costs when valued in BTC.

i think the biggest problem is with exchange and use in particular, as fees and confirmation times will be frustrating for a lot of cases. perhaps they will consider some sort of Lightning Network infrastructure, but that seems entirely too complex, while saying government will accept BTC puts all the cost of adoption on the individual.

i am still interested to see how this turns out.